A relay moves a movable contact provided on a tip of a plate spring by a suction force of a magnetic field generated when a current flows through a coil, and contacts the movable contact and a fixed contact. For this reason, in order to maintain a contact state, the relay needs to continue flowing the current and consumes an electric power continuously. Moreover, there is a problem that the contact state (i.e., ON state) of both contacts cannot be maintained at the time of a power failure.
For example, Japanese Laid-open Patent Publication No. 5-250950 and Japanese Unexamined Utility Model Publication No. 61-151242 disclose that a cam is rotated by exciting a coil, and a movable contact and a fixed contact are contacted mutually, with respect to a relay
On the contrary, a relay called a latching relay or the like can maintain a contact state by using a permanent magnet, a ratchet mechanism, or the like, without flowing a current. Therefore, the latching relay can reduce power consumption, and maintain the contact state at the time of power failure.
With respect to the latching relay, Japanese Unexamined Utility Model Publication No. 6-5087 discloses that a switch is configured so that a pair of contact boards repeats a contact state and a non-contact state whenever a coil of an electromagnetism plunger is energized by using a ratchet mechanism. Japanese Laid-open Patent Publication No. 63-126131, Japanese Laid-open Patent Publication No. 63-126132, and Japanese Examined Utility Model Publication No. 64-7555 disclose a relay which includes a lever that is pivotally mounted to a movable iron core, a latch receiver that is pivotally mounted to one end of the lever, a latch base that guides the movement of the latch receiver, a latch that is pivotally mounted to the latch base, and one end of the latch being engaged with the latch receiver.